The purpose of this study is to evaluate the standing function provided by various FES systems that control and regulate the stimulation to the paralyzed muscles. The specific aims of the study are to: 1) determine the response of paralyzed muscles to electrical stimulation; 2) analyze the ability to rise, stand, and sit with continous FES; and 3) develop new systems to control and automatically adjust the stimulation to maintain standing balance without using the hands or arms for support.